NumberResearch Membership · Data 09/19/2026

Recent prefix assignments

0 prefixes assigned in the last 30 days · from the daily NANPA CO code file, 09/19/2026

Full prefixes (NXX) Thousands-blocks (1,000-number pools)

The Code holder is who opened each NPA-NXX prefix — not necessarily who holds the numbers. A prefix is 10,000 numbers, but under pooling its ten 1,000-number blocks are handed out individually, often to different carriers; the code holder may hold only one block, or none. The Thousands-blocks column shows how the ten blocks are really split — click which blocks → to see who holds each 1,000-number block and its last-4-digit range. Assignments are initial assignments; the current serving carrier may differ due to portability.

Most active assignees, all time — NPA 570
CTSI, INC. - PA 33
New assignments by month Sep 2026 Aug 2026 Jul 2026 Jun 2026 May 2026 Apr 2026 Mar 2026 Feb 2026 Jan 2026 Dec 2025 Nov 2025 Oct 2025
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Recent NPA-NXX prefix assignments
AssignedNPA-NXXThousands-blocks taken (last-4 opening)Code holderOCNRate centerState
2013-04-19 570-703 0–9 XXXall 10 · 4 holders which blocks → CTSI, INC. - PA 7513 SCRANTON PA
2011-07-22 570-415 0–9 XXXall 10 · 7 holders which blocks → CTSI, INC. - PA 7513 SUNBURY PA
2010-02-19 570-591 0–9 XXXall 10 · 4 holders which blocks → CTSI, INC. - PA 7513 SCRANTON PA
2009-09-22 570-266 0–9 XXXall 10 · 4 holders which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
2006-10-26 570-915 0–9 XXXall 10 · 8 holders which blocks → CTSI, INC. - PA 7513 PINE GROVE PA
2006-10-26 570-968 0–9 XXXall 10 · 8 holders which blocks → CTSI, INC. - PA 7513 ORWIGSBURG PA
2006-06-27 570-808 0–9 XXXwhole prefix which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
2006-02-16 570-630 0–9 XXXall 10 · 6 holders which blocks → CTSI, INC. - PA 7513 LAKE ARIEL PA
— 570-207 not yet reported which blocks → CTSI, INC. - PA 7513 SCRANTON PA
— 570-208 not yet reported which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
— 570-258 2XXX4XXX5XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → CTSI, INC. - PA 7513 NANTICOKE PA
— 570-270 not yet reported which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
— 570-307 9XXX which blocks → CTSI, INC. - PA 7513 OLYPHANT PA
— 570-408 not yet reported which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
— 570-414 4XXX8XXX9XXX · 3 holders which blocks → CTSI, INC. - PA 7513 MOOSIC PA
— 570-416 2XXX3XXX4XXX6XXX7XXX8XXX9XXX · 6 holders which blocks → CTSI, INC. - PA 7513 BLOOMSBURG PA
— 570-501 not yet reported which blocks → CTSI, INC. - PA 7513 HAZLETON PA
— 570-517 1XXX4XXX6XXX8XXX9XXX · 2 holders which blocks → CTSI, INC. - PA 7513 STROUDSBG PA
— 570-552 not yet reported which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
— 570-558 not yet reported which blocks → CTSI, INC. - PA 7513 SCRANTON PA
— 570-601 2XXX4XXX5XXX7XXX8XXX · 4 holders which blocks → CTSI, INC. - PA 7513 WILLIAMSPT PA
— 570-602 not yet reported which blocks → CTSI, INC. - PA 7513 PITTSTON PA
— 570-613 2XXX3XXX4XXX5XXX8XXX · 3 holders which blocks → CTSI, INC. - PA 7513 WYOMING PA
— 570-714 not yet reported which blocks → CTSI, INC. - PA 7513 KINGSTON PA
— 570-715 4XXX5XXX6XXX8XXX · 2 holders which blocks → CTSI, INC. - PA 7513 MOUNTANTOP PA
— 570-718 2XXX3XXX4XXX5XXX7XXX8XXX9XXX · 6 holders which blocks → CTSI, INC. - PA 7513 KINGSTON PA
— 570-719 2XXX3XXX4XXX5XXX6XXX7XXX · 5 holders which blocks → CTSI, INC. - PA 7513 PLYMOUTH PA
— 570-770 0XXX1XXX3XXX4XXX5XXX6XXX7XXX8XXX9XXX · 2 holders which blocks → CTSI, INC. - PA 7513 SCRANTON PA
— 570-802 3XXX6XXX7XXX8XXX9XXX · 4 holders which blocks → CTSI, INC. - PA 7513 BERWICK PA
— 570-803 1XXX5XXX · 2 holders which blocks → CTSI, INC. - PA 7513 JERMYN PA
— 570-953 1XXX2XXX3XXX4XXX5XXX6XXX8XXX9XXX · 4 holders which blocks → CTSI, INC. - PA 7513 DANVILLE PA
— 570-970 not yet reported which blocks → CTSI, INC. - PA 7513 WILKSBARRE PA
— 570-975 1XXX2XXX3XXX4XXX5XXX6XXX7XXX9XXX · 2 holders which blocks → CTSI, INC. - PA 7513 SUNBURY PA

Source: NANPA CO Code Assignments (Utilized, All States, Public), file date 09/19/2026 — Tier A primary source, refreshed on every import. Viewing is free; bulk downloads require a membership.